Let-off and tension mechanism for narrow-ware looms



v N) FZIIGdlQLLFhIQZS Aug. 7, 1928. 1,679,634

c. A. STEERE LET-OFF AND TENSION MECHANISM FOR NARROW WARE LOOMS c/arezrce 14. sszeere Patented Aug. 7,1928.

UNITED CLARENCE A STEERE, OF wrcxr'on'n, RHODEJISLAND, Assrenoaro CROMPTON a KNOWLES LOOM worms, orWORC STER,.msseorrusn'r'rs, A CORPORATION or MASSACHUSETTS.

PA E T om LET-OFF AND TENSION MECHANISM roa NARROW-WARE LOOMS,

. Application fil ed .Ma s; 1925.. s ria fnb; 30,5 9.

This invention relates to a let-ofi' mechanism for a narrow ware loom. It' is the general practice in such looms to provide a separatebeam or spool for each separate narrow fabric in the loom. This involves much duplication of parts, with corresponding increase in cost, and also requires the winding of aconsiderable number of separate warp beams for each narrow ware loom." It is the object of my invention tof'provide a let-ofi -mechani sm so designed that a number of narrow warp sections'inay be taken from a single wide warp beam andthat each warp section may be separately tensioned and adjusted. e V I It is a further obiect of my invention to provide a construction'by which slackness in any warp section may be easily taken up and the tension restored independent of every otherrwarp section. vantageous'when a defect in weaving a particular narrow fabric necessitatesa pick out I of more or less length.

My invention further relates to arrangements and combinations of parts which will be hereinafter deseribedand more particularly pointed'out in the appended claimsl A preferred form of the invention is shown in the drawings, in which Y, A

Fig. 1 is a side elevation of parts-of a loom embodying my invention;

Fig. 2 is a rear elevationlof the parts shown in Fig. 1; and I I,

Fig. 3 is a front elevation v of the differ ential pulley, partly in section along the line 3 3 in Fig. 1.

Referring to the drawings, I have shown portion of a narrow ware loom having a frame on which a warp beam 11 is supported in bearings 12. The warp beam 11 is provided with friction drums or pulleys 13 at its ends, engagedcby friction bands 14. One end of each friction band is adjustably secured to a bracket 15 on the loom frame 10 and the other end of the band is pivotally connected at 16 to a lever 17 having a guide roll 18 pivotedat its outerend.

A. second guide roll 19 is rotatably mounted in fixed arms 20 secured to the loom frame and a third guide roll 21 is pivotally mounted at the outer end of levers 22, which levers arepivoted to the loom frame. Any desired number of weights W may be hung on the This is particularly ad- I outer ends of the levers 22. A fourth guide roll 24 is pivotedin fixed bearings 25 above the loom.- I a I A series of grooved pulleys or'sheaves 3O aremounted' in separate bearing members 31 in which they are freely rotatable.

bearing member 31 isflsupported by a rope or otherflex blemembcr 32 :which passes over a fixed-guide pulley 33 to asecond bearing member 34provided with a second sheave 35. The guide rolls '33 are mounted on fixed brackets 36 (Fig; 2) suitably secured above the'loom. 'i

A clifi'erential'pulley '40 for each sheave '35 1 p is mounted between the collars 41 (Fig. 3)

on a fixed shaft .42 secured in brackets 43 (Fig. -1)' fastened to the loom frame 10; The

pulley is provided with a larger? drum" portion 44 anda-smaller drum portion 45 and 'isalso providedwitha radial recess 46 in which is disposed a friction block .47 and an'adjusting screw 48. l

Arope 50 passes 'arou'n'dthe sheave-35 previously described and hasits two ends secured in flanges on the differential pulley 40," so that one end portion ofthe rope will be 'woundgin one direction'on the larger drum 4 1, whiletheother end portion of the rope will be wound in the opposite direction o'n'the'smallerdrum portion 45. Y Y

A separate sheave 30, rope 32, sheave 35,

method of use and the, operation thereof are as follows: The warp threads for each separate narrow fabric, such as a t-ape or ribbon,

foriir'a separate warp section S on the warp beam 11. vAll of these warps ections are led from thewar) beam 11 around theupper fixed guide-r0 l- 241 and back to the lower fixed guidefroll. 19. The warp'sectio'ns S thenpasssuccessively around the movable guide rolls 18 and 21 and to'the sheaves 30.

Each warp section S passes over its individual sheave 30 and then passes downward to a guide bar or whip roll (Fig. 1), from then pass upward which point it is led. forward through the- VVhen a harnesses to thefell ofthe fabric.

construction of "my 7 warp on the new warp is placed in the loom, the sheaves 30 are lowered to positions somewhat closely adjacent to the guide roll 24. This is accomplished by moving the rope 50 in such a direction as to wind the rope off of the large drum and on to the small drum, thus lengt 1- ening the free portion of the rope and permitting the sheave 35 to rise and the sheave 30 to be lowered.

The loom is then placed in operation and the tension on the warp is regulated by the weights W. The let-off action 'of the beam 11 is intermittent, as the warp pulls the weighted levers 22 upward until the levers 22 engage and lift the levers 17, thus releasin; the friction on the warp beam. i

The beam immediately starts to revolve and lets off a certain amount of warp, so that the levers 17 and 22 will swing down- .ward. Such action restores the friction on the brake beam 11 and also provides a certafn amount of free motion for the levers 22 before the lovers 17 are again lifted to release the friction. This intermittent let-off mechanism is of a usual type and in itself forms no part of my invention.

YVith the loom operating as described, let it be assumed that a defect occurs in one of the narrow fabrics and necessitating a pick out of considerable length. It is obviously impossible to turn the beam 11 backward, as a number of other warp sections on the same beam cannot be let back. At the same time slack warp has been produced in the section under repair and it is absolutely necessary for this slack warp -to be taken care of.

To accomplish this result, the operator merely pulls on the rope 50 in the direction of the arrow a, winding the rope off of the small drum and on to the large drum and thus shortening the free portion of the rope. This draws the sheave 35 downward and raises the sheave 30 to restorethe de sired warp tension to the warp section under repair, after which the loom continues to operate as before. The friction block 47 in the differential pulley is adjusted to hold the pulley 4L0 by friction in any desired position.

I have thus provided a very simple ar rangement by which the tension of any separate warp section may be adjusted as desired, independently of all other warp sections. The sheaves 30 are purposely placed as far as possible from the guide roll 21, so that the warp threads may be collected in the sheaves 30 without causing noticeable change of tension in the different threads,

due to the angles from which they approach the sheaves 80. r

' Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed otherwise than as set forth in the claims, but what I claim is i r 1. A narrow ware loom, having in commanually operable rotative means effective to positively change the path of travel of any selected warp section, and to definitely determine the length of sa1d path, manual means to positively vary and determine the length of warp between the warp beam and the fell of the fabric for any selected warp section, said means comprising a guide member for each warp section engaging the warp between the letofi mechanism the fabric, and manual means to changethe position of any selected guide member to a different definite position and to hold said member in its new position.

3. A narrow ware loom, comprising a.'let off and tension mechanism as set forth in claim'2, in which said manual means in cludes a sheave,'a differential pulley, a rope having its ends reversely secured to said pulley and its middle portion engaged by said sheave, and .a connection from said sheave to said guide member.

4:. A narrow ware loom, comprising a letoff and tension mechanism as set forth in claim 2, in which said manual means ineludes a sheave, a differentialjpulley, a rope having its ends reversely secured to said pulley and its m ddle portion engaged by said sheave, and a connectlon from sald having in com- I sheave. to said guide member, andin which a friction device is provided effective to yieldingly hold said differential pulley from-' rotation.

In testnnony whereof I have hereunto affixed my signature.

CLARENCE A. 'sfrnnnnf 

